1. Field of the Invention
The present invention relates to an apparatus measuring the mechanical characteristics of a body or medium, particularly the mechanical characteristics of the soil, enabling the following properties of the body or medium analysed to be measured and also, if desired, recorded: resistance to compression when subjected to a force, linear deformation resulting from the said force and also shear, cut or friction strength under the effect of a torque combined with a force exerted along an axis substantially perpendicular to the lever arm of the said torque and intersecting the latter approximately half way along it.
2. Discussion of the Prior Art
Many apparatuses of this kind have already been devised which are of weight and over-all size such that it can be transported by a man.
They may be classified in two categories depending upon their function:
penetrometers for measuring the resistance of the soil or any other medium to the penetration of a probe as a function of the depth of penetration of said probe (U.S. Pat. Nos. 2,130,751 and 3,712,121; German Pat. No. 1,216,574 and British Pat. No. 187,159; Bulletin CNEEMA B1 No. 237 October 1977 47-50; J. agric. Engng Res. (1977), 22, 209-212);
torsiometers able to measure the resistance of the soil or many other coherent medium to a shear and/or friction torque as a function of the compressive force having a direction perpendicular to the plane of the torque and to the plane of shearing and/or of friction (U.S. Pat. Nos. 3,116,633 and 3,797,301; Engineering Vol 199, No. 5159, Mar. 5, 1965) "Soil Shearing Meter" p. 315).
These measures are obtained via a digital meter or, for more sophisticated versions via a recording device requiring mostly very complicated appliance.
There is presently no lightweight device which may be used and carried by a single operator and which allows a combination of the both functions of the above measures i.e. penetrometric and torsiometric measures.
Only very heavy equipments are available for performing both penetrometric and torsiometric measures which depend on electro-hydraulic and/or pneumatic appliances (such as the BEVAMETER) and thus make necessary the use of teams of specialized operators and specific motor vehicles.